How Does Web Scraping Work

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About Price & Web Scraping Tools | Imperva

About Price & Web Scraping Tools | Imperva

What is web scraping
Web scraping is the process of using bots to extract content and data from a website.
Unlike screen scraping, which only copies pixels displayed onscreen, web scraping extracts underlying HTML code and, with it, data stored in a database. The scraper can then replicate entire website content elsewhere.
Web scraping is used in a variety of digital businesses that rely on data harvesting. Legitimate use cases include:
Search engine bots crawling a site, analyzing its content and then ranking it.
Price comparison sites deploying bots to auto-fetch prices and product descriptions for allied seller websites.
Market research companies using scrapers to pull data from forums and social media (e. g., for sentiment analysis).
Web scraping is also used for illegal purposes, including the undercutting of prices and the theft of copyrighted content. An online entity targeted by a scraper can suffer severe financial losses, especially if it’s a business strongly relying on competitive pricing models or deals in content distribution.
Scraper tools and bots
Web scraping tools are software (i. e., bots) programmed to sift through databases and extract information. A variety of bot types are used, many being fully customizable to:
Recognize unique HTML site structures
Extract and transform content
Store scraped data
Extract data from APIs
Since all scraping bots have the same purpose—to access site data—it can be difficult to distinguish between legitimate and malicious bots.
That said, several key differences help distinguish between the two.
Legitimate bots are identified with the organization for which they scrape. For example, Googlebot identifies itself in its HTTP header as belonging to Google. Malicious bots, conversely, impersonate legitimate traffic by creating a false HTTP user agent.
Legitimate bots abide a site’s file, which lists those pages a bot is permitted to access and those it cannot. Malicious scrapers, on the other hand, crawl the website regardless of what the site operator has allowed.
Resources needed to run web scraper bots are substantial—so much so that legitimate scraping bot operators heavily invest in servers to process the vast amount of data being extracted.
A perpetrator, lacking such a budget, often resorts to using a botnet—geographically dispersed computers, infected with the same malware and controlled from a central location. Individual botnet computer owners are unaware of their participation. The combined power of the infected systems enables large scale scraping of many different websites by the perpetrator.
Malicious web scraping examples
Web scraping is considered malicious when data is extracted without the permission of website owners. The two most common use cases are price scraping and content theft.
Price scraping
In price scraping, a perpetrator typically uses a botnet from which to launch scraper bots to inspect competing business databases. The goal is to access pricing information, undercut rivals and boost sales.
Attacks frequently occur in industries where products are easily comparable and price plays a major role in purchasing decisions. Victims of price scraping can include travel agencies, ticket sellers and online electronics vendors.
For example, smartphone e-traders, who sell similar products for relatively consistent prices, are frequent targets. To remain competitive, they’re motivated to offer the best prices possible, since customers usually go for the lowest cost offering. To gain an edge, a vendor can use a bot to continuously scrape his competitors’ websites and instantly update his own prices accordingly.
For perpetrators, a successful price scraping can result in their offers being prominently featured on comparison websites—used by customers for both research and purchasing. Meanwhile, scraped sites often experience customer and revenue losses.
Content scraping
Content scraping comprises large-scale content theft from a given site. Typical targets include online product catalogs and websites relying on digital content to drive business. For these enterprises, a content scraping attack can be devastating.
For example, online local business directories invest significant amounts of time, money and energy constructing their database content. Scraping can result in it all being released into the wild, used in spamming campaigns or resold to competitors. Any of these events are likely to impact a business’ bottom line and its daily operations.
The following is excerpted from a complaint, filed by Craigslist, detailing its experience with content scraping. It reinforces how damaging the practice can be:
“[The content scraping service] would, on a daily basis, send an army of digital robots to craigslist to copy and download the full text of millions of craigslist user ads. [The service] then indiscriminately made those misappropriated listings available—through its so-called ‘data feed’—to any company that wanted to use them, for any purpose. Some such ‘customers’ paid as much as $20, 000 per month for that content…”
According to the claim, scraped data was used for spam and email fraud, among other activities:
“[The defendants] then harvest craigslist users’ contact information from that database, and initiate many thousands of electronic mail messages per day to the addresses harvested from craigslist servers…. [The messages] contain misleading subject lines and content in the body of the spam messages, designed to trick craigslist users into switching from using craigslist’s services to using [the defenders’] service…”
Web scraping protection
The increased sophistication in malicious scraper bots has rendered some common security measures ineffective. For example, headless browser bots can masquerade as humans as they fly under the radar of most mitigation solutions.
To counter advances made by malicious bot operators, Imperva uses granular traffic analysis. It ensures that all traffic coming to your site, human and bot alike, is completely legitimate.
The process involves the cross verification of factors, including:
HTML fingerprint – The filtering process starts with a granular inspection of HTML headers. These can provide clues as to whether a visitor is a human or bot, and malicious or safe. Header signatures are compared against a constantly updated database of over 10 million known variants.
IP reputation – We collect IP data from all attacks against our clients. Visits from IP addresses having a history of being used in assaults are treated with suspicion and are more likely to be scrutinized further.
Behavior analysis – Tracking the ways visitors interact with a website can reveal abnormal behavioral patterns, such as a suspiciously aggressive rate of requests and illogical browsing patterns. This helps identify bots that pose as human visitors.
Progressive challenges – We use a set of challenges, including cookie support and JavaScript execution, to filter out bots and minimize false positives. As a last resort, a CAPTCHA challenge can weed out bots attempting to pass themselves off as humans.
Learn more about protecting your site from malicious bot traffic with Imperva’s bot management solution.
Is Web Scraping Legal ? - WebHarvy

Is Web Scraping Legal ? – WebHarvy

Web Scraping is the technique of automatically extracting data from websites using software/script. Our software, WebHarvy, can be used to easily extract data from any website without any coding/scripting knowledge.
Is it legal to scrape data from websites using software? The answer to this question is not a simple yes or no.
The real question here should be regarding how you plan to use the data which you have extracted from a website (either manually or via using software). Because the data displayed by most website is for public consumption. It is totally legal to copy this information to a file in your computer. But it is regarding how you plan to use this data that you should be careful about. If the data is downloaded for your personal use and analysis, then it is absolutely ethical. But in case you are planning to use it as your own, in your website, in a way which is completely against the interest of the original owner of the data, without attributing the original owner, then it is unethical, illegal.
Also, while extracting data from websites using software, since web scrapers can read and extract data from web pages more quickly than humans, care should be taken that the web scraping process does not affect the performance/bandwidth of the web server in any way. Most web servers will automatically block your IP, preventing further access to its pages, in case this happens.
Websites have their own ‘Terms of use’ and Copyright details whose links you can easily find in the website home page itself. The users of web scraping software/techniques should respect the terms of use and copyright statements of target websites. These refer mainly to how their data can be used and how their site can be accessed.
How to anonymously scrape data from websites?
Update: US federal court rules that web scraping does not violate hacking laws
Scrape Data Anonymously
WebHarvy is an easy-to-use visual web scraper which lets you scrape data anonymously from websites, thereby protecting your privacy. Proxy servers or VPNs can be easily used along with WebHarvy so that you are not connected directly to the web server during data extraction. Also, to minimize the load on web servers, and to avoid detection, there are options to automatically insert pauses & emulate a human user during the web scraping process.
What Is Web Scraping And How Does It Work? | Zyte.com

What Is Web Scraping And How Does It Work? | Zyte.com

In today’s competitive world everybody is looking for ways to innovate and make use of new technologies. Web scraping (also called web data extraction or data scraping) provides a solution for those who want to get access to structured web data in an automated fashion. Web scraping is useful if the public website you want to get data from doesn’t have an API, or it does but provides only limited access to the data.
In this article, we are going to shed some light on web scraping, here’s what you will learn:
What is web scraping? The basics of web scrapingWhat is the web scraping process? What is web scraping used for? The best resources to learn more about web scraping
What is web scraping?
Web scraping is the process of collecting structured web data in an automated fashion. It’s also called web data extraction. Some of the main use cases of web scraping include price monitoring, price intelligence, news monitoring, lead generation, and market research among many others.
In general, web data extraction is used by people and businesses who want to make use of the vast amount of publicly available web data to make smarter decisions.
If you’ve ever copy and pasted information from a website, you’ve performed the same function as any web scraper, only on a microscopic, manual scale. Unlike the mundane, mind-numbing process of manually extracting data, web scraping uses intelligent automation to retrieve hundreds, millions, or even billions of data points from the internet’s seemingly endless frontier.
Web scraping is popular
And it should not be surprising because web scraping provides something really valuable that nothing else can: it gives you structured web data from any public website.
More than a modern convenience, the true power of data web scraping lies in its ability to build and power some of the world’s most revolutionary business applications. ‘Transformative’ doesn’t even begin to describe the way some companies use web scraped data to enhance their operations, informing executive decisions all the way down to individual customer service experiences.
The basics of web scraping
It’s extremely simple, in truth, and works by way of two parts: a web crawler and a web scraper. The web crawler is the horse, and the scraper is the chariot. The crawler leads the scraper, as if by hand, through the internet, where it extracts the data requested. Learn the difference between web crawling & web scraping and how they work.
The crawler
A web crawler, which we generally call a “spider, ” is an artificial intelligence that browses the internet to index and search for content by following links and exploring, like a person with too much time on their hands. In many projects, you first “crawl” the web or one specific website to discover URLs which then you pass on to your scraper.
The scraper
A web scraper is a specialized tool designed to accurately and quickly extract data from a web page. Web scrapers vary widely in design and complexity, depending on the project. An important part of every scraper is the data locators (or selectors) that are used to find the data that you want to extract from the HTML file – usually, XPath, CSS selectors, regex, or a combination of them is applied.
The web data scraping process
If you do it yourself
This is what a general DIY web scraping process looks like:
Identify the target websiteCollect URLs of the pages where you want to extract data fromMake a request to these URLs to get the HTML of the pageUse locators to find the data in the HTMLSave the data in a JSON or CSV file or some other structured format
Simple enough, right? It is! If you just have a small project. But unfortunately, there are quite a few challenges you need to tackle if you need data at scale. For example, maintaining the scraper if the website layout changes, managing proxies, executing javascript, or working around antibots. These are all deeply technical problems that can eat up a lot of resources. There are multiple open-source web data scraping tools that you can use but they all have their limitations. That’s part of the reason many businesses choose to outsource their web data projects.
If you outsource it
1. Our team gathers your requirements regarding your project.
2. Our veteran team of web data scraping experts writes the scraper(s) and sets up the infrastructure to collect your data and structure it based on your requirements.
3. Finally, we deliver the data in your desired format and desired frequency.
Ultimately, the flexibility and scalability of web scraping ensure your project parameters, no matter how specific, can be met with ease. Fashion retailers inform their designers with upcoming trends based on web scraped insights, investors time their stock positions, and marketing teams overwhelm the competition with deep insights, all thanks to the burgeoning adoption of web scraping as an intrinsic part of everyday business.
What is web scraping used for?
Price intelligence
In our experience, price intelligence is the biggest use case for web scraping. Extracting product and pricing information from e-commerce websites, then turning it into intelligence is an important part of modern e-commerce companies that want to make better pricing/marketing decisions based on data.
How web pricing data and price intelligence can be useful:
Dynamic pricingRevenue optimizationCompetitor monitoringProduct trend monitoringBrand and MAP compliance
Market research
Market research is critical – and should be driven by the most accurate information available. High quality, high volume, and highly insightful web scraped data of every shape and size is fueling market analysis and business intelligence across the globe.
Market trend analysisMarket pricingOptimizing point of entryResearch & developmentCompetitor monitoring
Alternative data for finance
Unearth alpha and radically create value with web data tailored specifically for investors. The decision-making process has never been as informed, nor data as insightful – and the world’s leading firms are increasingly consuming web scraped data, given its incredible strategic value.
Extracting Insights from SEC FilingsEstimating Company FundamentalsPublic Sentiment IntegrationsNews Monitoring
Real estate
The digital transformation of real estate in the past twenty years threatens to disrupt traditional firms and create powerful new players in the industry. By incorporating web scraped product data into everyday business, agents and brokerages can protect against top-down online competition and make informed decisions within the market.
Appraising Property ValueMonitoring Vacancy RatesEstimating Rental YieldsUnderstanding Market Direction
News & content monitoring
Modern media can create outstanding value or an existential threat to your business – in a single news cycle. If you’re a company that depends on timely news analyses, or a company that frequently appears in the news, web scraping news data is the ultimate solution for monitoring, aggregating, and parsing the most critical stories from your industry.
Investment Decision MakingOnline Public Sentiment AnalysisCompetitor MonitoringPolitical CampaignsSentiment Analysis
Lead generation
Lead generation is a crucial marketing/sales activity for all businesses. In the 2020 Hubspot report, 61% of inbound marketers said generating traffic and leads was their number 1 challenge. Fortunately, web data extraction can be used to get access to structured lead lists from the web.
Brand monitoring
In today’s highly competitive market, it’s a top priority to protect your online reputation. Whether you sell your products online and have a strict pricing policy that you need to enforce or just want to know how people perceive your products online, brand monitoring with web scraping can give you this kind of information.
Business automation
In some situations, it can be cumbersome to get access to your data. Maybe you need to extract data from a website that is your own or your partner’s in a structured way. But there’s no easy internal way to do it and it makes sense to create a scraper and simply grab that data. As opposed to trying to work your way through complicated internal systems.
MAP monitoring
Minimum advertised price (MAP) monitoring is the standard practice to make sure a brand’s online prices are aligned with their pricing policy. With tons of resellers and distributors, it’s impossible to monitor the prices manually. That’s why web scraping comes in handy because you can keep an eye on your products’ prices without lifting a finger.
Learn more about web scraping
Here at Zyte (formerly Scrapinghub), we have been in the web scraping industry for 12 years. With our data extraction services and automatic web scraper, Zyte Automatic Extraction, we have helped extract web data for more than 1, 000 clients ranging from Government agencies and Fortune 100 companies to early-stage startups and individuals. During this time we gained a tremendous amount of experience and expertise in web data extraction.
Here are some of our best resources if you want to deepen your web scraping knowledge:
What are the elements of a web scraping project? Web scraping toolsHow to architect a web scraping solutionIs web scraping legal? Web scraping best practices

Frequently Asked Questions about how does web scraping work

Is web scraping legal?

Web Scraping is the technique of automatically extracting data from websites using software/script. … Because the data displayed by most website is for public consumption. It is totally legal to copy this information to a file in your computer.

How does a web scraper work?

The web data scraping process Identify the target website. Collect URLs of the pages where you want to extract data from. Make a request to these URLs to get the HTML of the page. … Save the data in a JSON or CSV file or some other structured format.

Is web scraping harmful?

Further, data scraping can open the door to spear phishing attacks; hackers can learn the names of superiors, ongoing projects, trusted third parties, etc. Essentially, everything a hacker could need to craft their message to make it plausible and provoke the correct (rash and ill-informed) response in their victims.Aug 24, 2020

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